Embroidery sewing machine and method

ABSTRACT

An embroidery sewing machine includes a machine body carrying a needle, a shuttle and a bobbin. A cutter is disposed in proximity to the needle to cut a thread end portion of an upper thread that extends out of an eye of the needle so that the thread end portion has an adjusted length after being cut by the cutter. The needle, shuttle and bobbin are controlled to perform an initial stitching operation that pulls the thread end portion from an upper side of a fabric to an under side thereof and that produces a fixing stitch beneath the fabric to prevent the upper thread from being loosened. An embroidering method is also disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a sewing machine, and more particularly to anembroidery sewing machine having a cutter and an embroidery sewingmethod using the sewing machine.

2. Description of the Related Art

Nowadays, most decorative embroidery patterns, which are formedconventionally by hand, have been made using embroidery sewing machines.However, most conventional embroidery sewing machines have a drawback inthat a fabric embroidered thereby has an end portion of an upper thread,which extends out from an eye of a needle, and is usually left on anupper side of a fabric when an embroidery pattern is formed by theconventional embroidery sewing machines on the fabric. The end portionof the upper thread visible on the upper side of the fabric isdetrimental to the aesthetic appearance of the embroidery pattern. Whilethe thread end portion visible on the upper side of the fabric may beremoved by cutting, the need to cut the thread end portion istime-consuming and inconvenient.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an embroidery sewingmachine that can pull a thread end portion of an upper thread from anupper side of a fabric to an under side of the fabric.

According to one aspect of the invention, an embroidering method isprovided using an embroidery sewing machine, which includes a needle, ashuttle and a bobbin to operate upper and lower threads. Theembroidering method comprises: (a) providing a cutter that is located ata predetermined distance from the needle to cut a thread end portion ofan upper thread, which extends out from an eye of the needle, so thatthe thread end portion has an adjusted length; and (b) controlling theneedle, the shuttle and the bobbin to operate the upper and lowerthreads to perform an initial stitching operation on a fabric forpulling the thread end portion from an upper side of the fabric to anunder side of the fabric. The initial stitching operation includes thefollowing sub-steps: (i) moving downward the needle from an uppermostpoint to a lowermost point wherein the thread end portion is pulleddownward to the underside of the fabric, but a terminating end of thethread end portion is kept to remain on the upper side of the fabric;and (ii) moving upward the needle from the lowermost point to theuppermost point while operating the shuttle to pull and form the upperthread that passes through the fabric into a loop and to interlace theloop with the lower thread, wherein the terminating end of the threadend portion is pulled downward to the underside of the fabric.

According to another aspect of the invention, an embroidery sewingmachine comprises: a machine body having a base, a support extendingupward from the base, a sewing head suspended from the support, and aneedle plate disposed on the base below the sewing head; a needlemovably mounted to the sewing head and having an eye through which anupper thread passes; a shuttle unit mounted in the base; a bobbindisposed in the shuttle and holding a lower thread; and a cutterdisposed in proximity to the needle to cut a thread end portion of theupper thread that extends out of the eye of the needle so that thethread end portion has an adjusted length after being cut by saidcutter.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiments with reference to the accompanying drawings, of which:

FIG. 1 is a perspective view of a preferred embodiment of an embroiderysewing machine according to the present invention;

FIG. 2 is a fragmentary perspective view of the preferred embodiment;

FIG. 3 is a fragmentary elevation view of the preferred embodiment;

FIG. 4 is a block diagram illustrating how a shuttle and a bobbin arerelated to a drive unit and an electrical control; and

FIGS. 5-9 illustrates successive operating steps employed in an initialstitching operation for pulling a thread end portion of an upper threadfrom an upper side of a fabric to an under side of the fabric.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1-5, an embroidery sewing machine according to apreferred embodiment of the present invention may be used to form anembroidery pattern on a fabric 400 by operating an upper thread 200 anda lower thread 300. The embroidery sewing machine includes a machinebody 1, a needle 2, a shuttle 31, a bobbin 32, a cutter 4, a drive unit5 and an electrical control unit 6.

The machine body 1 has a base 11, an upstanding support 12 extendingfrom the base 11, a sewing head 13 suspended from the support 12, and aneedle plate 14.

The needle 2 is mounted on the sewing head 13 above the needle plate 14,and is movable upward and downward relative to the needle plate 14. Theneedle has an eye for passage of the upper thread 200.

The shuttle 31 is disposed rotatably in the base 11 below the needleplate 14. The bobbin 32 is disposed within the shuttle 31. The lowerthread 300 is held within the bobbin 32 and has a portion extendingoutwardly from the bobbin 32.

The cutter 4 is installed on the sewing head 13 in proximity to theneedle 2 and is used to cut a thread end portion 201 of the upper thread200 that extends out of the eye of the needle 2. The cutter 4 has acutter seat 41 mounted on the sewing head 13, and a cutter blade 42mounted on the cutter seat 41. The cutter blade 42 is arranged to have apredetermined distance from the needle 2, which is about 4.5 cm.Therefore, when the thread end portion 201 of the upper thread 200 ispulled from the needle 2 to the cutter 4 and is cut by the cutter blade42, the thread end portion 201 after being cut will have an adjustedlength of about 4.5 cm.

While the cutter 4 is mounted on the sewing head 13 in this embodiment,it may also be mounted on any other suitable part of the machine body,which is proximate to the needle 2. The distance of the cutter 4 fromthe needle 2 may also be 4 cm, or 5 cm. Therefore, the distance of thecutter 4 is preferably in a range of 4-5 cm.

As shown in FIG. 4, the electrical control unit 6 is connectedelectrically to the drive unit 5, and the drive unit 5 is connectedmechanically to the shuttle 31 and the bobbin 32. The drive unit 5 iscontrolled by the electrical control unit 6 to drive the shuttle 31 andthe bobbin 32.

The embroidery sewing machine of the present invention may operate topull down the thread end portion 201 from an upper side of the fabric400 to an under side of the fabric 400. The needle 2, the shuttle 31 andthe bobbin 32 may be controlled by the electrical control unit 6 tooperate the upper and lower threads 200, 300 to perform an initialstitching operation for pulling the cut thread end portion 201 to theunder side of the fabric 400. An embroidering method is exemplifiedbelow and includes steps (A) to (C).

Referring to FIG. 5, in step (A), the upper thread 200 is passed throughan eye of the needle 2 and has the thread end portion 201 extending outof the eye of the needle 2 on the upper side of the fabric 400. Thelength of the thread end portion 201 is adjusted by cutting the threadend portion 201 using the cutter 4. The adjusted length of the threadend portion 201 is about 4.5 cm.

In step (B), the needle 2, the shuttle 31 and the bobbin 32 arecontrolled by the drive unit 5 and the electrical control unit 6 tooperate the upper and lower threads 200, 300 to perform an initialstitching operation on the fabric 400 for pulling the thread end portion201 from an upper side of the fabric 400 to an under side of the fabric400. The initial stitching operation including the following sub-steps:

(b-1) The needle 2 is moved downward from an uppermost point to alowermost point through the fabric 400 and pulls the thread end portion201 to the under side of the fabric 400. But, a terminating end of thethread end portion 201 is kept to remain on the upper side of the fabric400.

(b-2) Referring to FIGS. 6, 7 and 8, the needle is moved upward from thelowermost point toward the uppermost point while the shuttle 31 is beingoperated to pull and form the upper thread 200 that passes through thefabric 400 into a loop 202 and to interlace the loop 202 with the lowerthread 300. In particular, the upper and lower threads 200, 300 areinterlaced by causing the loop 202 of the upper thread 200 to looparound the lower thread 300. During the upward movement of the needle 2,the upper thread 200 is pulled and the loop 202 is tightened gradually.When the needle 2 reaches the uppermost point, the loop 202 is formedinto a tightened knot 203, and the terminating end of the thread endportion 201 is completely pulled downward to the underside of the fabric400.

Referring to FIG. 9, in step (C), the downward and upward movements ofthe needle 2 carried out in step (B) are repeated at least twice tointerlace and form the upper and lower threads 200, 300 into a fixingstitch 204 that fixes the upper thread 200 to the fabric 400 so that theupper thread 200 is prevented from becoming loosened.

Because the thread end portion 201 is hidden beneath the fabric 400, itdoes not affect the aesthetic appearance of the embroidery patternformed at the upper side of the fabric 400. Therefore, it is notnecessary to cut the thread end portion 201 of the upper thread from thefabric 400.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiments, it isunderstood that this invention is not limited to the disclosedembodiment but is intended to cover various arrangements included withinthe spirit and scope of the broadest interpretation so as to encompassall such modifications and equivalent arrangements.

1. An embroidering method using an embroidery sewing machine, whichincludes a needle, a shuttle and a bobbin to operate upper and lowerthreads, the embroidering method comprising: (a) providing a cutter thatis located at a predetermined distance from the needle to cut a threadend portion of an upper thread, which extends out from an eye of theneedle, so that the thread end portion has an adjusted length; (b)controlling the needle, the shuttle and the bobbin to operate the upperand lower threads to perform an initial stitching operation on a fabricfor pulling the thread end portion from an upper side of the fabric toan under side of the fabric, the initial stitching operation includingthe following sub-steps: (i) moving downward the needle from anuppermost point to a lowermost point wherein the thread end portion ispulled downward to the underside of the fabric, but a terminating end ofthe thread end portion is kept to remain on the upper side of thefabric; and (ii) moving upward the needle from the lowermost point tothe uppermost point while operating the shuttle to pull and form theupper thread that passes through the fabric into a loop and to interlacethe loop with the lower thread, wherein the terminating end of thethread end portion is pulled downward to the underside of the fabric. 2.The embroidering method of claim 1, wherein the upper and lower threadsare interlaced by causing the loop of the upper thread to loop aroundthe lower thread and by tightening the loop during the upward movementof the needle to reach the uppermost point.
 3. The embroidering methodof claim 2, wherein the sub-steps (i) and (ii) is repeated at leasttwice to interlace the upper and lower threads to form a fixing stitchthat fixes the upper thread to the fabric.
 4. The embroidering method ofclaim 1, wherein the predetermined distance of the cutter from theneedle is 4-5 cm.
 5. An embroidery sewing machine comprising: a machinebody having a base, a support extending upward from said base, a sewinghead suspended from said support, and a needle plate disposed on saidbase below said sewing head; a needle movably mounted to said sewinghead and having an eye through which an upper thread passes; a shuttleunit mounted in said base; a bobbin disposed in said shuttle and holdinga lower thread; and a cutter disposed in proximity to said needle to cuta thread end portion of said upper thread that extends out of said eyeof said needle so that said thread end portion has an adjusted lengthafter being cut by said cutter.
 6. The embroidery sewing machine asclaimed in claim 5, wherein said cutter includes a cutter seat mountedto said sewing head, and a cutting blade mounted to said cutter seat. 7.The embroidery sewing machine as claimed in claim 6, wherein a distanceof said cutter from said needle is about 4-5 cm so that said thread endportion has a length of about 4-5 cm after being cut by said cutter. 8.The embroidery sewing machine as claimed in claim 5, further comprisingan electrical control unit, and a drive unit controlled by saidelectrical control unit to operate said shuttle and said bobbin.
 9. Theembroidery sewing machine as claimed in claim 8, wherein said needle,said shuttle and said bobbin are operated by said drive unit to performan initial stitching operation, during which: said needle is moveddownward from an uppermost point to a lowermost point; said thread endportion is pulled downward to the underside of the fabric while aterminating end of said thread end portion is being kept to remain onthe upper side of the fabric; and when said needle moves upward from thelowermost point to the uppermost point, said shuttle is operated to pulland form said upper thread that passes through the fabric into a looparound said lower thread, and the terminating end of said thread endportion is pulled downward to the underside of the fabric.